Putative antagonistic effects of mycorrhiza waitea circinata against colletotrichum falcatum causing agent red rot in sugarcane

Abstract

Brazil is the world’s largest producer of sugarcane; however, the crop suffers significant losses due to red rot caused by Colletotrichum falcatum. Hence, biocontrol strategies, such as the use of the mycorrhizal fungus Waitea circinata, which has demonstrated efficacy against rice pathogens, has been evaluated for the integration into management approaches. This study assessed the secretion of lytic enzymes during conidial germination and appressoria formation in C. falcatum induced by W. circinata. All experiments were conducted using a completely randomized design. Nine different mycorrhizal suspensions were used to evaluate conidial germination and appressorium formation, alongside the quantification of the activities of β-1,3-glucanase, chitinase, and protease enzymes. W. circinata inhibited C. falcatum by 70.5% and reduced conidial germination and appressorium formation by 84.8% and 92.7%, respectively, at a concentration of 60 g L−1, with a significant increase in the activity of the analyzed enzymes. In terms of antagonistic effects, β-1,3-glucanase, chitinase, and protease activities at all assessment times were higher when compared to the pathogen alone, supporting the results observed for conidial germination and appressorium formation. Thus, W. circinata acting through antibiosis and the secretion of lytic enzymes showed its potential as a bioagent in the sustainable management of red rot disease.